DCI 1_2 TCI State Mapping Under Limited Codepoints

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Solution Overview

Problem

Existing wireless communication systems face challenges in efficiently indicating transmission configuration indicator (TCI) states due to limitations in the number of codepoints in downlink control information (DCI) format 1_2, which can lead to inefficiencies and increased network overhead.

Innovation Solution

The system employs a mechanism to utilize a subset of activated TCI states using a reduced number of codepoints in DCI format 1_2, allowing for effective application of TCI states even when the available codepoints are insufficient, thereby optimizing resource allocation and reducing retransmissions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the number of codepoints in DCI format 1_2 is increased to indicate more TCI states, then the completeness of TCI state indication is improved, but the size of DCI increases leading to higher network overhead

Engineering Contradiction:

Improvecompleteness of TCI state indicationVSAvoidDCI size

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent segments the TCI state indication process into two parts: (1) A subset of TCI states is indicated directly in DCI format 1_2 using a compact indicator field with limited codepoints, and (2) The remaining TCI states are indicated through separate RRC signaling or MAC CE mechanisms. This segmentation allows the DCI to remain compact while the complete set of TCI states can still be fully specified through combination with other signaling layers.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent moves part of the TCI state indication from the time-critical DCI domain to the higher-layer RRC/MAC CE domain, effectively adding a dimensional aspect to the indication mechanism. This allows DCI to focus on urgent, frequently changing TCI states with minimal overhead, while less time-sensitive TCI configurations are handled through higher-layer signaling with larger capacity.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Quantity of substance

If the number of codepoints in DCI format 1_2 is reduced to minimize network overhead, then the network overhead is reduced, but the ability to indicate all activated TCI states is lost

Engineering Contradiction:

Improvenetwork overheadVSAvoidcompleteness of TCI state indication

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent applies preliminary action by pre-configuring a mapping relationship between the limited codepoints in DCI format 1_2 and a larger set of TCI states. This mapping is established through higher-layer RRC signaling before data transmission, allowing the compact DCI indicator to reference pre-defined TCI state combinations, thereby achieving both compact DCI size and complete TCI state indication capability.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary mapping mechanism that bridges the gap between the limited DCI codepoints and the full set of activated TCI states. This intermediary layer, established through RRC configuration, allows indirect indication of TCI states without requiring direct one-to-one mapping in DCI, thus reducing DCI overhead while maintaining indication completeness.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If more TCI states are activated to improve transmission flexibility, then the adaptability of the system is improved, but the complexity of managing and indicating these states increases

Engineering Contradiction:

Improvetransmission flexibilityVSAvoidTCI state management complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent segments TCI state management into different operational layers: frequent, dynamic TCI state selections are handled through compact DCI indicators for rapid adaptation, while less frequent TCI state configurations are managed through higher-layer RRC/MAC CE mechanisms. This segmentation reduces the real-time processing complexity at the UE while maintaining support for a large number of activated TCI states.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent implements dynamic TCI state indication where the effective TCI state is determined by combining information from multiple sources: the compact DCI indicator providing dynamic, transmission-specific selection, and pre-configured RRC parameters providing the foundation set of available TCI states. This dynamic combination allows flexible adaptation to changing channel conditions while keeping device complexity manageable through hierarchical state management.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentEP4214886B1Transmission configuration indicator states in downlink control information format 1_2

Publication Date: 2026.03.18 QUALCOMM INC

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AI summary

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, from a base station, downlink control information (DCI) in format 1_2 that includes an indicator with a first quantity of codepoints that is smaller than a second quantity of activated transmission configuration indicator (TCI) states. Accordingly, the UE may apply a TCI state, from the first quantity of activated TCI states out of the second quantity of activated TCI states, according to the indicator. Numerous other aspects are described.